The present invention relates to a video printing apparatus and a ribbon cartridge usable in the apparatus.
A thermal ink ribbon for video printers is well known in the art. The ink ribbon includes an elongated substrate film and color layer formed on the substrate film. The color layer has a plurality of color blocks arranged in series. Each of the color blocks comprises segments arranged in a predetermined order, for example, yellow, magenta and cyan colors, respectively. One color block with segments is used for printing one sheet. A positioning mark is applied at a leading end of an initial one of the serial color blocks so as to indicate a start position of printing operation. Such an ink ribbon is wound up on a reel disposed in a cartridge case so as to be used as an ink ribbon cartridge. Two types of the ink ribbon cartridge are generally known, which are single-reel and double-reel types. The single-reel type cartridge has one reel for supply of the ink ribbon while the double-reel type cartridge has two reels used for supply and take-up of the ink ribbon, respectively.
However, since neither the video printer nor the ink ribbon cartridge has means for counting the number of the color blocks used for printing, a remaining volume of the ink ribbon can not be ascertained upon using the ink ribbon cartridge in a conventional video printer. In addition, ascertainment whether the ink ribbon is used or unused can be performed only by visual detection. Particularly, upon replacing the single-reel type cartridge with another one of the same type, the ink ribbon must be rewound up on the reel in the cartridge prior to removing the cartridge from the printer. Therefore, upon reusing the single-reel type cartridge, an unused part of the ink ribbon can not be readily found. Accordingly, in case that the ink ribbon cartridge is of such a single-reel type, the ink ribbon is undesirably wasted due to the undetection of an unused part of the ink ribbon upon use of the cartridge.
An object of the present invention is to provide a video printing apparatus capable of detecting used or unused state of color blocks of an ink ribbon and the number of used color blocks, so that the remaining volume of unused portions of the ink ribbon and a leading end of the unused portions are ascertained.
Another object of the present invention is to provide an ink ribbon cartridge for video printing apparatus, which serves for representing the number of used color blocks of an ink ribbon.